Last Friday, the day Israeli planes poured bombs on the Palestinian quarter of Beirut, was a bad day for the PLO. With 300 or more of its followers lying dead, it proved that the PLO was powerless to confront the Israeli war machine. Yet, if anything, the bombing seemed to intensify the Palestinians' resolve to go on with the struggle. I heard no boasting or bravado in my talks with them. They made no claim that the lobbing of a few rockets into Kiryat Shemona was in any way comparable in size, skill or technology to the forces that Israel could concentrate against them.

The bombing did aggravate the sense of helplessness and despair Palestinians almost uniformly seem to feel. But it also provided painful reaffirmatin of a message I heard over and over again: we have no choice. It was like the "ain breira" that drove Israel on for years. The Palestinians face a dilemma in which events -- most of which seem to them to be under Israel's control -- are persistently narrowing their options. The bombing seemed to say to them that, if they give up now, the might not survive.

Since concentrating its resources here, in the wake of the 1970 Black September disaster in Jordan, the PLO has extended its authority over the 400,000 to 500,000 Palestinian refugees in Lebanon. Within the context of Lebanese feudalism, it runs one of the most effective and responsible governments in the country.

With Persian Gulf oil money, the PLO has built hospitals and public health services, schools and day care centers, factories and workshops. Like the other feudal authorities, it collects "taxes," but its leaders, Yasser Arafat first among them, have never been said to profit personally. For the Palestinians here, the PLO is not simply a symbol of resistance but a benevolent government presence.

In the Lebanese civil war, the PLO is allied to the anit-Phalangist national movement, which endlessly proclaims its devotion to Arab solidarity. But the Palestinians are still considered outsiders by the Lebanese.

Most of the PLO's leadership now believes it committed a mistake in playing such an aggressive role in the early part of the civil war. Recently, it has attempted to hold a low profile. One reason is a sense that the PLO has already expended too much of its energy in the last five years fighting Arab Lebanese with whom it has no long-term quarrel. Another is a certain apprehension over what might happen if there is a settlement to the civil war, or a victory.

A victory of the Phalangists, who would restore a Maronite Christian republic, would present the most immediate threat. But a victory of the "left" would also be a problem. Khomeini's Iran has given new influence to the Shiia population, who have lost control of their land in the south to the Palestinians and to Israel's designs and who would like to see the Palestinians neutralized.

The best the Palestinians can hope for in Lebanon is the status quo. Ironically, Israel, by keeping Lebanon in a condition of disarray, may actually be playing into their hands.

Palestinians can count even less on a warm reception elsewhere in the Arab world. Jordan, in a sense the most generous place, is unlikely to welcome a further influx of refugees, especially if they insist on bringing their PLO apparatus with them. Syria maintains tight control over Palestinians within its borders, while the Gulf employs Palestinians but denies them permanent residence.

Thanks to the absence of central government, only in Lebanon have the Palestinians been free to live something resembling a life of their own. But now this appears jeopardized by Israeli firepower, on the one hand, and by possible political changes among the Lebanese, on the other.

At this point, what the Palestinians would like is to reach a compromise with Israel, so they can return to at least a segment of the land that once was theirs. The PLO has said as much officially in a resolution of the Palestine Natinal Congress, its "parliament." Unofficially, its message is that, in the interest of a haven as much as of a homeland, it will con sider any reasonable offer.

Under Israeli fire, however, the PLO concludes that compromise is impossible with Israel in its current state of mind, and that Israel will be satisfied with nothing less than the total decimation of the structure of Palestinian life.

The Europeans smile at them weakly, and the Americans offer them a cold shoulder and furnish the Israelis with the planes that attack them.

This is why Palestinians say they have no choice but to continue the armed struggle no matter how long it takes. And if the rockets that fall on Kiryat Shemona, killing three, unleash a bombing on Beirut, illing 300, they say they will accept the price.